Probably means probably. On the same (wrong) line of thinking we can't say humans can walk because some of them can't. Not all birds fly as well... besides,

Probably means probably. On the same (wrong) line of thinking we can't say humans can walk because some of them can't. Not all birds fly as well... besides, some animals are better than others for testing purpose. Mice are well known for having a great memory, testing mice for memory makes sense. Recent studies proved that mice memory cells work on experiences and not on places, just like ours.